The first year will involve the standardization of the assay using four coded chemicals for the purpose of judging the utility of the assay at the end of the first year. The contractor will also use two standard carcinogens for the purpose of optimizing the sensitivity of the serum-free assay for anchorage independence and focus formation. Methods for selecting for a neoplastic phenotype will also be evaluated using the standard carcinogens. If the results from the first year are judged to be satisfactory, the contract will continue. During years two through five, the contractor will test coded chemicals. Additionally, for this four year period, the contractor will conduct in-depth studies of the induction of anchorage independence, focus formation, and other parameters of transformation.